[1] Mansell suffered a significant quad injury in early 2018, hampering his output during the national academy series season with the Mariners.

[5] Mansell was eventually selected to represent Tasmania as a member of The Allies side at the 2018 AFL Under 18 Championships, but missed two games as a result of the earlier quad injury.

[9][10] As an overage player in 2019, Mansell joined the newly re-formed Tasmania Devils side in the Victorian-based NAB League Boys competition, where he placed fourth in the club's best and fairest.

[17][18] He contributed a strong 19 disposals, eight marks and five tackles while playing as a half-back in the club's grand final victory over North Adelaide.

[21] Mansell impressed during his trial and in February 2021, was signed by the club under the AFL's pre-season supplemental selection rules.

[22] Mansell began playing practice matches with Richmond reserves squad from late-February 2021 and into the opening weeks of the AFL season.